Benoit Panizzon
2012-Mar-27 12:06 UTC
[asterisk-users] chan_sip.c:3641 retrans_pkt: Retransmission timeout
Hello We have a Genband C3 Switch and a couple of customers that operate asterisk PBXes connected via SIP Trunk. All of them still use some 1.6.X asterisk and this works fine. One customer uses a 1.8 version and has a very strange problem: Asterisk 1.8.10.0-1digium1~lucid built by pbuilder @ nighthawk on a x86_64 running Linux on 2012-03-06 01:51:21 UTC When a call reaches this asterisk the call get's dropped after a couple of seconds with this message: [Mar 27 13:47:35] WARNING[29806]: chan_sip.c:3641 retrans_pkt: Retransmission timeout reached on transmission F47F6F67 at 7f33ff47 for seqno 907689273 (Critical Response) -- See https://wiki.asterisk.org/wiki/display/AST/SIP+Retransmissions Packet timed out after 6400ms with no response [Mar 27 13:47:35] WARNING[29806]: chan_sip.c:3670 retrans_pkt: Hanging up call F47F6F67 at 7f33ff47 - no reply to our critical packet (see https://wiki.asterisk.org/wiki/display/AST/SIP+Retransmissions). Well, the Wiki is not very helpfull, as the problems explained there do not seem to be the cause. I sniffed the connection on the Asterisk Box itself and what I see is this flow of SIP messages: C3 <=> Asterisk => Invite +sdp <= 401 Unauthorized => Ack => Invite +sdp +auth <= 100 Trying <= 180 Ringing <= RTP Audio <= 200 OK +sdp => Ack <=> RTP Audio <= 200 OK +sdp => Ack <= 200 OK +sdp => Ack <= 200 OK +sdp => Ack <= Bye => Ack <= Bye => Ack <= Bye => Ack Well apparently the C3, from my point of view sends correct Acks to the Asterisk, but somehow the Asterisk ignores them. I did try to get more information with debug and verbose level set to '99', but I don't see more messages Does anyone have a clue, why acks could be not accepted by asterisk 1.8.10.0 ? The other way round (asterisk => c3) the calls work fine. Regards Benoit Panizzon -- I m p r o W a r e A G - ______________________________________________________ Zurlindenstrasse 29 Tel +41 61 826 93 07 CH-4133 Pratteln Fax +41 61 826 93 02 Schweiz Web http://www.imp.ch ______________________________________________________